Excerpts from Christophe Leroy's message of January 14, 2021 12:50 am: > > > Le 13/01/2021 à 08:32, Nicholas Piggin a écrit : >> Add context tracking to the system call handler explicitly, and remove >> _TIF_NOHZ. >> >> This saves 35 cycles on gettid system call cost on POWER9 with a >> CONFIG_NOHZ_FULL kernel. > > 35 cycles among 100 cycles, or among 5000 cycles ? I meant what pourcentage > to you win ?
I can re-check when I update and retest. On the order of about 500 IIRC, so quite significant proportion of the cost. Thanks, Nick
